Advanced Channel Emulator
dBm
Operations Manual
ACE600
35
Lo o p
Press the
Loop
key to togg
le between “Single” and “Continuous”. In
“Single”, parameter files are run from beginning to end, and then
execution stops, and the mode changes to DONE. In “Continuous”,
files are repeatedly run from beginning to end. Mode remains at RUN.
Files can only be run in Continuous looping under the following
conditions:
1.
the first data point and the last data point in the file are identical. If
Continuous is selected, and all selected parameter files do not have
matching end points, Loop will automatically revert
to “Single”.
All selected files must indicate “Loop:
Continuous” in order for
“continuous” to be active. If
loaded files have unequal run times,
the last point of the shorter file(s) is held until the last point of the
longest file is executed, and then execution stops
Up d a te Ra te Ke y
Press the
Update Rate
key to select the update rate field. The update
rate field is highlighted.
Type a value for update period.
Press
Enter
. The new value is entered and the pointer disappears.
Valid values are 1, 2, 5, 10, 20, 50, 100, 200, 500, and 1000 ms. Invalid
entries are rounded to the nearest valid number.
There are three update rates. The first one, controls the rate for all of
the parameters that appear on the dynamic delay display, namely,
delay, attenuation, frequency offset, phase offset, and AWGN. The
second update rate controls the RF Frequency rate, and the third
controls the multipath update rate. Each can be set on the respective
display, but there is a dependency between them. See the
Dynamic
Timin
g Control”
section for a more detailed description.
Up d a te Clo c k S o u rc e Ke y
Press the
Update Clock
key to toggle between an internally and
externally applied update clock. When set to internal, the update clock
is generated internally. The internal clock is derived from an internal
timer. The accuracy of the internal timer is based on the accuracy of the
10 MHz reference clock. When set to external, the instrument executes
one parameter datum on each external rising clock edge, after a START
signal is received. The external clock is a 3.3V logic level signal that is
applied at the external timing input connector at the rear of the
instrument.
Trig g e r S o u rc e Ke y
Press the
Trigger Source
key
to toggle between “Internal” and
“External”. When set to “Internal”, file execution begins when a Start
command is received from the front panel or via an Ethernet command.
Latency of the software generated command can cause start time
uncertainty when using this type of trigger.
When set to “External”, the Start command
arms the instrument, and
file execution begins on the 2nd update clock after the receipt of the
rising edge of a 3.3V logic level trigger signal applied to the trigger
Continuous looping only functions when all loaded file run times are equal.
File run time is the number of file data points times the update rate for that
file. Example: 100 data points at a 5 msec update interval is a run time of
500 msec.
